Mullion assembly



y 1967 A. E. HAND 3,319,382

MULLION AS SEMBLY Filed Aug. 24, 1964 5 Sheets-Sheet 1 i i 1 u g f I A? IINVENTOR.

A; B5)? 7' E. H/mm.

May 16, 1967 A. E. HAND 3, 2

MULLION AS SEMBLY Filed Aug. 24, 1964 I; Sheets-Sheet 2 7 I i f r a w I I n IN VEN TOR May 16, 1967 A. E. HAND MULLION ASSEMBLY 5 Sheets-Sheet Filed Aug. 24, 1964 INVENTOR. /ZL. RT E. HHND.

United States Patent Ofifice 3,319,382 Patented May 16,1967

3,319,382 MULLION ASSEMBLY Albert E. Hand, Southington, Conn, assignor to Emhart Corporation, Bloomfield, Conn., a corporation of Connecticut Filed Aug. 24, 1964, Ser. No. 391,678 18 Claims. (Cl. 49--504) This invention relates to a mullion assembly and more particularly to a mullion assembly for installation between the threshold .and the head jamb of a double door opening for adapting said door opening to receive a pair of single doors carrying rim-type emergencyexit locks.

The primary object of this invention is to provide a mullion assembly including a mullion post and mounting means therefor which are so designed as to permit facile installation of the mullion post as well as quick and easy removal thereof when it is desired to utilize the full, double door opening.

A most important object of this invention is to provide a mullion assembly having new and improved mounting means for attaching the mullion post to its mounting plates, said means completely eliminating the need for using separate screws or like fastening elements between these parts.

A further object of the present invention is to provide a mullion assembly in which the mounting means for the mullion post are designed to securely hold the mullion post against movement thereby preventing rattles or malfunctioning of the door locks.

An extremely novel feature of this invention is the provision of a mullion assembly in which the strike plates for the door locks are adapted to be mounted on the mullion post without the use of interconnecting screws and are both vertically and horizontally adjustable to permit accurate positioning thereof with respect to the latchbolts of the door locks.

Still another object of this invention is to provide a mullion assembly in which the mounting plate for the lower end of the mullion post is adapted for use, either with or without a threshold plate.

Further objects and advantages of the present invention will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings, which, by way of preferred ex ample only, illustrate certain specific embodiments of the invention.

Referring now to the drawings:

FIG. 1 is a top plan view partly in horizontal section, illustrating the mullion assembly of the present invention as it would be installed in a double door opening for cooperation with a pair of single doors equipped with rimtype emergency exit locks.

FIG. 2 is a foreshortened side elevational view further illustrating the manner in which my novel mullion assembly is installed.

FIG. 3 is a front elevational view of the mullion assembly illustrated in FIG. 2.

FIG. 4 is a plan view illustrating the underside of the upper mounting plate for the mull-ion post.

FIG. 5 is a fragmentary front view taken in central vertical section, illustrating the mullion post and the upper mounting means therefor.

FIG. 6 is a view similar to FIG. 5 illustrating the mullion post and the upper mounting means fully assembled.

FIG. 7 is a bottom plan view, taken on line 77 of FIG. 6, further illustrating the upper mounting means.

FIG. 8 is a top plan view, partially in section, illustrating the mullion post and the lower mounting plate therefor.

FIG. 9 is a sectional side view further illustrating said mullion post and said lower mounting plate.

FIG. 10 is a side view, partially in section, illustrating the lower mounting plate for the mullion post as applied to a threshold equipped with a threshold plate.

FIG. 11 is a sectional front view of the lower end portion of the mullion post further illustrating the lower mounting plate therefor.

FIG. 12 is .a top plan View, partially in section, illustrating the mullion post and the manner in which the strike plates for the door locks are mounted thereon.

FIG. 13 is a similar view, further illustrating the mounting means for the strike plates.

FIG. 14 is a View similar to FIG. 13 illustrating additional details of the strike plate mounting arrangement.

FIG. 15 is an elevational front view, partially in section, further illustrating said strike plates and the mounting means therefor.

FIG. 16 is an elevational view illustrating the inner side of the strike plate assembly.

FIG. 17 is an exploded, isometric view of the strike plate assembly illustrating the various parts thereof.

Referring now to the drawings, and especially to FIGS. 1 through 3 thereof, it will be seen that the mullion assembly of the present invention includes an elongated tubular mullion post 5 which is preferably made of sheet metal and formed by any suitable process to provide the cross-sectional configuration illustrated. The particular design of the mullion post permits manufacture thereof in long lengths which may be cut to size to conform to the height of the door opening in which the mullion post is to be installed.

As best illustrated in FIG. 1, the mullion post 5 is in the form of an elongated, one-piece, tubular member of generally square cross section having spaced parallel front and rear walls 6 and 7, respectively, and side walls formed to provide channels 8-8 in the opposite sides of said mullion post extending for the entire length thereof. The said channels include spaced parallel bottom walls 99 and side walls 10-10 which are inwardly divergent so that each of said channels is of dovetail configuration, as best illustrated in FIG. 1. The mullion post 5 is mounted in vertical position between the head jamb 11 and the threshold 12 of a door opening by novel mounting means which include upper and lower mounting plates 13 and 14, respectively, and carries on its opposite sides a pair of strike plates 15-15 adapted to receive the latchbolts 16-16 extending from a pair of emergency-exit locks 17--17 that are mounted on doors 18-18 which close against the front wall 6 of the mullion post as shown in FIG. 1.

As a novel feature of my invention, I provide mounting means for the mullion post 5 which eliminate the need for drilling and tapping the mullion post and which perr'nit quick and easy installation thereof. Moreover, the said mounting means permit facile removal of the mullion post should it become necessary to utilize the full door opening for one reason or another.

As previously indicated, the mounting means of the present invention include upper and lower mounting plates 13 and 14, respectively. Referring to FIGS. 4 through 8, it will be seen that the upper mounting plate 13 is of generally rectangular shape and has a substantially flat body portion 19 provided with countersunk holes such as indicated at 20 for the reception of screws or like fastening elements for attaching the mounting plate to the head jamb 11. At its opposite ends, the body portion 19 has integral, U-shaped bosses 21-21 depending therefrom in opposed, spaced relation. Each of said bosses includes an end wall 22 and spaced parallel side walls 23-43. The end walls 22-22 extend below the side walls 23-23, for a purpose to be described, and the side and end walls of the respective bosses define opposed recesses 24-24 in the underside of the mounting plate which extends laterally in opposite directions from a transverse slot 25 forming a passageway defined by the opposed ends of the side walls 23-23.

The upper end portion of the mullion post is adapted to fit into the slot 25, between the ends of the side walls 23-23 of the bosses 21, and when so disposed, the channels 8-8 are located opposite the recesses 24-24 in said bosses as best illustrated in FIG. 7.

In accordance with the present invention, I provide locking means for securely and firmly locking the upper end of the mullion post to the upper mounting plate 13. Said locking means include a pair of locking members 26-26 L-shaped in cross section, each having a vertical leg portion 27 adapted to fit slidably in a respective one of the channels 8-8 in the mullion post and a horizontal leg portion 28 which projects laterally from the respective channel and is adapted to be received in the recess 24 in the adjacent boss 21 and in close fitting relation to the side walls 23-23 thereof as illustrated in FIG. 7. Each of the end walls 22-22 of the bosses 21 is provided with a centrally located, transversely extending, threaded hole 29 having a set screw 30 threaded thereto. The said screws are utilized to secure the locking members 2626 in locking position and, to this end, the outer ends of the horizontal legs 28-28 thereof are provided with angled abutment surfaces 31 engageable by said screws, each of said screws being upwardly inclined and disposed normal to its respective abutment surface and thereby adapted to exert an upward force on its respective locking member which tends to bias same upwardly and into tight locking engagement with the post 5. It will be noted from FIG. 7 that the vertical leg 27 of each of the locking members 28 is of dovetail configuration, conforming closely to the shape of its respective channel 8. As a result, the locking members are free to slide vertically in said channels, but are prevented from being removed laterally therefrom; this construction greatly facilitates installation of the mullion post.

The mullion assembly of the present invention also includes novel means for mounting the lower end of the mullion post. Referring to FIGS. 8 through 11, said lower mounting means comprises a mounting plate 32 including a flat base portion 33 having an integral, upstanding boss 34 thereon. The sides of the boss 34 are spaced inwardly from the corresponding sides of the base 33 so that said boss will fit snugly into the mullion post, and the upper portions of the sides of said boss are tapered to facilitate assembly of the said post thereto. The base portion 33 of the lower mounting plate is preferably made so that its overall dimensions substantially correspond to the external dimensions of the mullion post. This not only eliminates any obstructions in the door opening over which people passing therethrough might possibly trip, but also provides an installation having a neat and attractive appearance. In the embodiment of the invention illustrated, the said lower mounting plate is provided with three vertically extending holes 35 therethrough to receive screws or like fastening elements for securing the mounting plate to the threshold of the door opening.

It is contemplated that the mullion assembly of the present invention will be installed in door openings both with and without a conventional threshold plate. In order to adapt said lower mounting plate for either application, I form same with a transverse notch 36 in the underside thereof which is shaped to substantially conform to the contours of a standard threshold plate indicated by the numeral 37 in FIG. 9. To permit use of the mounting plate 32 on a threshold where there is no threshold plate present, as at 38 in FIG. 9, I provide a filler block 39 for insertion into the notch 36. The upper face of the said filler block is shaped to conform to the contour 0f the notch 36 and is provided with a centrally located upstanding projection 40 adapted to fit into a recess 41 extending upwardly from the notch 36 for positioning the filler block 39 relative to the mounting plate. As will be apparent from FIGS. 8 and 9, the said filler block is provided with a vertical hole that is aligned with the corresponding hole in the mounting plate to permit a fastening screw to pass therethrough.

In order to install the mullion of the present invention, the lower mounting plate 32 and the upper mounting plate 13 are first secured to the threshold 38 and the head ja'mb 11, respectively, in vertically aligned relationship. Of course, the tiller block 39 for the lower mounting plate will be used if the door opening has a flush threshold or, in the event that the door opening is provided with a threshold plate, the filler block will be discarded and the lower mounting plate secured in position over the outer edge of the threshold plate as shown in FIG. 10. After the upper and the lower mounting plates have been installed, the locking members 2626 are inserted one into each of the channels 8-8 in the mullion post and the said post is then placed over the upstanding boss 34 of the lower mounting plate and at an angle thereto as indicated in dotted lines in FIG. 9. The mullion post is then pressed downwardly and, at the same time, swung outwardly toward the vertical. Since the exterior dimensions of the boss 34 are slightly greater than the interior dimensions of the mullion post, the side Walls of the mullion post will be cammed outwardly to a slight extent as the mullion post moves toward its vertical position, thereby providing a tight fit with the boss 34 which will efiectively prevent rattles. As the mullion post approaches its vertical position, its upper end is guided into the slot 25 in the upper mounting plate and, when the channels 8-8 in the opposite sides of the mullion post are aligned with the recesses 24-24 in the bosses 21-21, the locking members 2626 are moved up into locking position within said recesses and secured therein by the locking screws 30-30, thereby completing the installation of the mullion post. It will be understood that my novel mounting arrangement provides for mounting the mullion post firmly and against movement in all directions without the use of separate screws.

The present invention also provides novel means for mounting the strike plates for the latchbolts 16-16 of the locks 17-17 on the mullion post. Referring now to FIGS. 12 through 17 inclusive, the said strike plates each comprise a flat plate 42 of rectangular shape which is wider than its respective channel 8 of the mullion post and is provided with an opening 43 therethrough adapted to receive the latchbolt-of the respective lock 17 as best illustrated in FIG. 1. The said plate 42 is supported on a base member 44 comprising a flat, C-shaped supporting plate 45 having integral outer leg portions 46-46 extending perpendicularly from its upper and lower edges. The said plate 45 is provided with a central cutout 47 between upper and lower inner leg portions 48-48 which are spaced from and extend parallel to the outer leg portions 46-46. The portion of the plate 45 between each pair of legs 46 and 48 is provided with an elongated, horizontally extending slot 49 and the strike plate 42 is provided with vertically spaced holes 50-50 which are alignable with said slots.

The said supporting plate 45 is adapted to slide vertically in its respective channel 8 in the mullion post and, to this end, each of the leg portions 46 is provided with opposed, laterally extending spurs 51-51 which conform to the cross-sectional shape of the channel and serve to slidably retain the supporting plate 45 therein. It will also be noted from FIGS. 12 and 15 that the inner free edges 52-52 of the said leg portions are adapted to rest upon the bottom of the respective channel and, when so disposed, the outer face of the supporting plate projects slightly beyond the ribs defining said channel so that the inner face of the strike plate will be slightly spaced therefrom.

The supporting plate 45 is retained in adjusted position in its respective channel 8 by a pair of elongated clamping members 53-53. Each of said clamping members is of U-shaped, cross-sectional configuration and includes a pair of spaced parallel leg portions E i-54 connected by an integral web portion 55. The said clamping members are adapted to fit between the leg portions 46 and 48 of the supporting plate 45, as shown in FIGS. 15 and 16, and the web portions thereof are provided with elongated slots 5656 that are alignable with the slots 4949 in the said supporting plate.

The leg portions 5454 of the clamping members 53-53 are also provided with opposed, laterally extending spurs 5757 which also conform to the cross-sectional shape of the respective channel 8 of the mullion post and the outer angled edges of which are adapted to engage the angularly disposed side walls of said channels for a purpose to be presently describedv The strike plate 42 is secured to the supporting plate 45 and clamped in adjusted position on the mullion post by a pair of flat-head screws 5858 which extend through the holes 50-50 in the strike plate 42 and through the slots 4949 and 5656 in the supporting plate 45 and clamping members 53-53, respectively. At their inner ends, the said screws 5858 are threaded into square nuts 59--59 which sli-dably fit between the leg portions 5454 of their respective clamping members 5353 and are thus prevented from rotating. When the screws 5858 are tightened, the clamping members 53-53 will be drawn outwardly to cause the spurs 5'7 thereon to engage the angularly disposed side walls of the respective channel 8. The supporting plate 45 will then be urged inwardly against the bottom wall of the channel to provide a rigid support for the strike plate carried thereby.

The strike plate assemblies are inserted into their respective channels before the mullion post is mounted and may thereafter be moved into proper position with relation to the latchbolts. It will be apparent that the entire strike plate assembly in each of the channels of the mullion post may be moved vertically therein to align the opening 43 of the strike plate with the respective latchbolt 16 and that the strike plate 42 itself may be adjusted horizontally to effect proper engagement of the latchbolt with the outer edge of the opening 43, said horizontal adjustment being permitted by the slots 49 and 56in the supporting plate and clamping members, respectively.

While I have herein shown and described my invention in what I consider to be the most practical and preferred embodiment thereof, it is recognized that departures may be made therefrom within the scope of my invention which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the appended claims so as to embrace any and all equivalent apparatus.

I claim:

1. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening and having longitudinally extending channels formed in opposite sides thereof, a mounting plate adapted to be attached to the structure defining said door opening for securing one end of said mullion post thereto, said mounting plate having spaced pairs of abutments disposed, respectively, adjacent said opposite sides of said mullion post, and locking members inserted into said channels and having portions fitting between said abutments whereby to lock said end of the mullion post to said mounting plate.

2. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening and having longitudinally extending channels formed in opposite sides thereof, a mounting plate adapted to be attached to the structure defining said door opening for securing one end of said mullion post thereto, said mounting plate having recesses formed therein adjacent said opposite sides of said mullion post, and locking members inserted into said channels and having portions fitting into said recesses for locking said end' of the mullion post to said mounting plate.

3. The subject matter set forth in claim 2 wherein said mounting plate is provided with spaced bosses between which said end of the mullion post is adapted to fit and said recesses are formed in said bosses.

4. The subject matter set forth in claim 3 wherein each of said bosses is provided with a threaded hole and a screw for securing said locking members in locking position.

5. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening and having longitudinally extending channels formed in the opposite sides thereof, a mounting plate adapted to be attached to the structure defining said door opening for securing one end of said mullion post thereto, said mounting plate having spaced bosses thereon disposed, respectively, adjacent said opposite sides of said mullion post and defining a cavity therebetween which receives the end portion of said mullion post, said bosses having opposed laterally extending recesses formed therein communicating with said cavity, and a pair of locking members inserted one into each of said channels and having portions fitting into said recesses to thereby lock said end of the mullion post to said mounting plate, and a screw threaded into each of said bosses and engaged with the respective locking member, for securing said locking member in locking position.

6. The subject matter set forth in claim 5 wherein said screws are arranged to urge said locking members into clamping engagement with the bottom walls of their respective channels whereby to clamp said end of the mullion member therebetween.

7. In a mullion assembly for installation between the threshold and the head jamb of a door opening, an elongated mullion post adapted to be mounted vertically between said threshold and said head jamb, said mullion post having longitudinally extending channels in the opposite sides thereof, each of said channels being of generally dovetail shape in cross section and including a bottom wall and spaced converging side walls, a pair of strike plates mounted one on each said opposite side of said mullion post and each having an opening therein for the reception of the latchbolt of a door lock, and means for adjustably securing each of said strike plates to said mullion post including a supporting plate slida-ble in the respective channel and engaged with the bottom wall thereof, a clamping member disposed between said supporting plate and said bottom wall and having laterally extending portions engaged with the side walls of said channel, and fastening means extending through said strike plate, said supporting plate and said clamping member for drawing said members together whereby to clamp said assembly in adjusted position in said channel.

8. The subject matter set forth in claim 7 wherein said supporting plate and said clamping member have elongated slots extending horizontally therein to permit horizontal adjustment of said strike plate relatively to said mullion post.

9. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted in said door opening, means for securing the upper end of said post to the head jamb ofsaid opening, a mounting plate for securing the lower end of said post to the threshold of said opening, said mounting plate having a notch in the bottom thereof to receive a threshold plate, the said notch being provided with a removable filler plate.

10. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening, means for securing the upper end of said post to the head jamb of said opening, a mounting plate for securing the lower end of said post to the threshold of said opening, said mounting plate having a notch in the bottom thereof to receive a threshold plate, a removable filler plate fitting in said notch, and fastening means for securing said mounting plate to the threshold, said fastening means including axially aligned holes extending through said mounting and filler plates.

11. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening, means for securing the upper end of said post to the head jamb of said opening, a mounting plate for securing the lower end of said post to the threshold of said opening, said mounting plate having a notch in the bottom thereof to receive a threshold plate, a removable filler plate fitting in said notch, and a projection on one of said plates fitting in a recess in the other plate for aligning said plates in assembled position.

12. In a mullion assembly for adapting a door opening to receive a pair of doors, an elongated mullion post adapted to be mounted vertically in said door opening, means for securing the upper end of said post to the head jamb of said opening, a mounting plate for securing the lower end of said post to the threshold of said opening, said mounting plate having a notch in the bottom thereof to receive a threshold plate, a filler plate fitting in said notch, and a vertical projection on said filler plate fitting in a recess in the bottom of said mounting plate for retaining said plates in aligned position.

13. In a mullion assembly for installation between the threshold and the head jamb of a door opening, the combination of an elongated tubular mullion post having channels of dovetail cross-sectional configuration extending longitudinally in the opposite sides thereof, a lower mounting plate adapted to be secured to said threshold for positioning the lower end of said mullion post thereon, said lower mounting plate including a base portion having upwardly extending boss thereon fitting within the lower end portion of said mullion post, said boss being of a height such that said lower end portion of the mullion post may be placed on said base portion and swung into a vertical position over said boss when pivoted about the lower edge thereof in a direction parallel to said sides of the mullion post, said boss being of greater maximum width than the interior width of said mullion post whereby said mullion post is distorted to provide a tight fit with said boss, an upper mounting plate adapted to be secured to said head jamb and having a cavity in the underside thereof receiving the upper end portion of said mullion post and recesses extending laterally in opposite directions from said cavity with which the channels in the opposite sides of said mullion post are aligned, a pair of locking members slidable one in each of said channels and having portions fitting into said recesses for locking the upper end of said mullion post to said upper mounting plate, a strike plate on each of the opposite sides of said mullion post and clamping means sliding within said channels for clamping said strike plates in different positions along :said mullion post, said clamping means permitting adjustment of said strike plates crosswise of said mullion post.

14. In a mullion assembly for installation between the threshold and the head jamb of a door opening, the combination of an elongated mullion post having channels extending longitudinally in the opposite sides thereof, a lower mounting plate adapted to be secured to said threshold for positioning the lower end of said mullion post thereon, an upper rnounting plate adapted to be secured to said head jamb and having a cavity in the underside thereof receiving the upper end portion of said mullion post and recesses extending laterally in opposite directions from said cavity with which the channels in the opposite sides of said mullion post are aligned, a pair of locking members slidable one in each of said channels and having portions fitting into said recesses for locking the upper end of said mullion post to said upper mounting plate, a strike plate on each of the opposite sides of said mullion post and clamping means slidably mounted within said channels for clamping said strike plates in diiferent positions along said mullion post, said clamping means also permitting adjustment of said strike plates crosswise of said mullion post.

15. In a mullion assembly for adapting a door opening in a door frame to receive a pair of doors; an elongated mullion post adapted to be mounted vertically in said door opening, said mullion post having longitudinally extending channels formed in the opposite sides thereof, each of said channels having undercut side walls, said mullion post further having at least a hollow lower end; means for securing the lower end of said post in said opening, said means including a mounting plate which is shaped to conform to a frame threshold and which has an upwardly projecting portion fitting snugly and tightly into said hollow lower end of said mullion post, said portion being shaped to permit said mullion post to be placed thereover and tilted to its vertical position in said door opening; and means for securing the upper end of said mullion post in said door opening, said securing means including locking members slidably inserted into said undercut channels and means for fastening said locking members to said door frame.

16. A structure as set forth in claim 15 including at least one strike plate slidably mounted in one of said vertical channels, said strike plate having clamping means slidable in said channel for securing said strike plate in different positions along said mullion post.

17. A structure as set forth in claim 16, wherein said clamping means for said strike plate has means for horizontal as well as vertical adjustment of said strike plate relative to said mullion post.

18. In a mullion assembly for adapting a door opening in a door frame to receive a pair of doors; an elongated tubular mullion post adapted to be mounted vertically in said door opening, said mullion post having pairs of spaced beads formed respectively on opposite sides thereof extending for the entire length of said mullion post and defining channels with undercut side walls; means for securing the lower end of said post in said opening, said means including a mounting plate which is shaped to conform to a frame threshold and which has an upwardly projecting portion fitting snugly and tightly into the hollow, tubular lower end of said mullion post, said portion being shaped to permit said mullion post to be placed thereover and tilted to its vertical position in said door opening; and means for securing the upper end of said mullion post in said door opening closely adjacent said frame, said securing means including locking members slidably inserted into said undercut channels and means for fastening said locking members to said door frame.

References Cited by the Examiner UNITED STATES PATENTS 2,356,309 8/1944 Gar'be 52-731 2,696,028 12/1954 Miller 20--64 3,000,062 9/1961 McCandless 52-204 3,189,140 6/1965 Luss 2019 FOREIGN PATENTS 729,805 5/ 1955 Great Britain.

HARRISON R. MOSELEY, Primary Examiner.

KENNETH DOWNEY, Examiner. 

1. IN A MULLION ASSEMBLY FOR ADAPTING A DOOR OPENING TO RECEIVE A PAIR OF DOORS, AN ELONGATED MULLION POST ADAPTED TO BE MOUNTED VERTICALLY IN SAID DOOR OPENING AND HAVING LONGITUDINALLY EXTENDING CHANNELS FORMED IN OPPOSITE SIDES THEREOF, A MOUNTING PLATE ADAPTED TO BE ATTACHED TO THE STRUCTURE DEFINING SAID DOOR OPENING FOR SECURING ONE END OF SAID MULLION POST THERETO, SAID MOUNTING PLATE HAVING SPACED PAIRS OF ABUTMENTS DISPOSED, RESPECTIVELY, ADJACENT SAID OPPOSITE SIDES OF SAID MULLION POST, AND LOCKING MEMBERS INSERTED INTO SAID CHANNELS AND HAVING PORTIONS FITTING BETWEEN SAID ABUTMENTS WHEREBY TO LOCK SAID END OF THE MULLION POST TO SAID MOUNTING PLATE. 